Adding a View Step

Follow the instructions below to add a step to a data layer that creates a custom view of the data but does not change the source or materialize new data by default. View steps use SPARQL CONSTRUCT queries to create a view definition in AnzoGraph.

1. In the Anzo application, expand the Blend menu and click Graphmarts. Anzo displays a list of the existing graphmarts. For example:

   

2. On the Graphmarts screen, click the name of the graphmart that you want to change.
3. Click the Data Layers tab. Anzo displays the existing data layers.
4. Click the menu icon () on the layer for which you want to create a step, and then select Add Step/View. Anzo opens the Add step dialog box.

   

5. Follow one of the options in this step, depending on whether you want to create a step from scratch or clone an existing view step for reuse:
   • If you want to create a new step, select View, and then click OK. Anzo opens the Create view step screen. Proceed to the next step.

     

   • If you want to clone an existing step and add it to this layer, click the Existing Views tab and follow these steps:
     1. Select the view that you want to clone and click OK. Anzo displays the Clone dialog box, which asks if you want to copy the permissions from the existing step.

        

     2. On the Clone dialog box, click Yes to copy the permission configuration from the existing step or click No to copy the step without the permission configuration.

        Anzo clones the step, adds the copy to the layer, and returns to the Data Layers screen.

     3. On the Data Layers screen, click the menu icon () on the cloned step and select Edit. Anzo opens the Edit load data step screen. Proceed to the next step.
6. On the Details tab, type a name for the step in the Title field and add an optional description in the Description field.
7. If you want to store a copy of the data that the view creates (materialize the data), select the Materialize the view when activated... check box. When this option is disabled Anzo creates a virtual view where only the view definition is stored in memory and not a copy of the data.
8. By default the Enabled option is selected, indicating that the step is enabled and will run when the layer is loaded. If you want to disable the step so that it is not processed, clear the Enabled check box.
9. Click the Source drop-down list and configure the source data for this step. Steps can build upon the data generated by steps in other layers or can be self-contained, applying changes that relate only to the data defined in the layer that contains this step. You can select any number of the following options:
   • Self: This option is selected by default and means that the query runs against only the data that is generated in the layer to which this step belongs.
   • All Previous Layers Within Graphmart: Choosing this option means that the query runs against the data that is generated by all of the layers in the graphmart that precede this layer.
   • Previous Layer Within Graphmart: Choosing this option means that the query runs against only the data that is generated by the one layer that precedes this layer.
   • Layer Name: The Source drop-down list also includes options for specific layer names. You can choose a specific layer to run the query against only the data that is generated by that layer.

     You can remove any of the source options by clicking the X to the left of the option name.

10. Click the Data models drop-down list and select the model or models to run this query against.

11. In the Query field, compose the CONSTRUCT query that creates the view of the data that you want to see. You can use the following syntax as a template for the query:

    CONSTRUCT {
    }
    ${fromSources}
    ${fromNamedSources}
    WHERE { 
      GRAPH ?graph {
     }
    }

    Do not include a GRAPH keyword in the CONSTRUCT clause as Anzo uses the view's URI as the graph URI for the constructed triples. In addition, Anzo uses the configured Source data options to automatically replace the ${fromSources} and ${fromNamedSources} variables with the appropriate FROM clauses when the query runs.

    For more information about CONSTRUCT queries, see CONSTRUCT in the W3C SPARQL 1.1 Query Language specification.

12. Click Save to add the step to the data layer. Anzo adds the step as the last step in the layer. If you want to change the order of the steps, click the black bar on the left side of a step and drag it up or down.

The Hi-Res Analytics tab for view steps contains advanced settings that control how the layer is exposed to and affects Hi-Res Analytic queries. Changing these settings can have unexpected consequences. Cambridge Semantics recommends that you do not modify the Hi-Res Analytics settings unless you understand the repercussions. To learn about the advanced settings, see Hi-Res Analytics Settings Reference.

Related Topics

• Adding Steps to Data Layers
• SPARQL Query Templates and Best Practices